1. Rinse fish; pat dry with paper towels. Lightly sprinkle salmon with salt and pepper. Place 2 tablespoons of the barbecue sauce in small bowl; brush sauce on both sides of the salmon.
2. For charcoal grill, cook salmon on greased grill rack directly over medium coals for 8 to 12 minutes or until salmon flakes when tested with a fork, turning once halfway through grilling. (For gas grill, preheat grill. Reduce heat to medium. Place salmon on greased grill rack over medium heat. Cover and grill as above.)
3. For nectarine salsa, in medium bowl combine nectarines, blueberries, pecans, and the remaining 1 tablespoon barbecue sauce. Season with salt. Serve salmon with salsa and lemon wedges.